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[PATCH v4 7/7] spi: imx: defer spi initialization, if DMA engine is pending

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If SPI device supports DMA mode, but DMA controller is not yet
available due to e.g. a delay in the corresponding kernel module
initialization, retry to initialize SPI driver later on instead of
falling back into PIO only mode.

Signed-off-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com>
Signed-off-by: Anton Bondarenko <anton.bondarenko.sama@gmail.com>
---
 drivers/spi/spi-imx.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index aaa32c2..c2edd0f 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -1341,9 +1341,15 @@ static int spi_imx_probe(struct platform_device *pdev)
 	 * Only validated on i.mx6 now, can remove the constrain if validated on
 	 * other chips.
 	 */
-	if (is_imx51_ecspi(spi_imx) &&
-	    spi_imx_sdma_init(&pdev->dev, spi_imx, master))
-		dev_err(&pdev->dev, "dma setup error,use pio instead\n");
+	if (is_imx51_ecspi(spi_imx)) {
+		ret = spi_imx_sdma_init(&pdev->dev, spi_imx, master);
+		if (ret == -EPROBE_DEFER)
+			goto out_clk_put;
+
+		if (ret < 0)
+			dev_err(&pdev->dev, "dma setup error %d, use pio\n",
+				ret);
+	}
 
 	spi_imx->devtype_data->reset(spi_imx);
 
-- 
2.6.3

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Thread

[PATCH v4 0/7]  Improvements for SPI IMX driver for Freescale IMX51, IMX53 and IMX6 Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 3/7] spi: imx: add support for all SPI word width for DMA transfer Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 1/7] spi: imx: Fix DMA transfer Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
    Re: [PATCH v4 1/7] spi: imx: Fix DMA transfer Sascha Hauer <s.hauer@pengutronix.de> - 2015-11-30 09:30 +0100
  [PATCH v4 7/7] spi: imx: defer spi initialization, if DMA engine is pending Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 2/7] spi: imx: replace fixed timeout with calculated one Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 6/7] spi: imx: return error from dma channel request Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100
  [PATCH v4 5/7] spi: imx: Add support for loopback for ECSPI controllers Anton Bondarenko <anton.bondarenko.sama@gmail.com> - 2015-11-28 00:20 +0100

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